Injection Lance Assembly

ABSTRACT

The system and method for preventing air leakage from the process side to the bearing side of a mill. The system includes a labyrinth seal ring comprising a series of knives defining first and second labyrinth paths from an air inlet to the process side and the bearing side of the system, respectively. The differences in the two paths such as provided by the number of knives used in each path creates a differential pressure drop which biases air from the air inlet to the process side. The labyrinth seal thus provides a reliable and superior method for reducing the potential for particulate in the process side of the mill from damaging the bearing system.

FIELD OF INVENTION

The present invention relates to a system and method for more efficienttreatment of pollutants from a fluid stream in a dry sorbent injectionprocess. Specifically, the present invention relates to an injectionlance assembly for creating a higher degree of turbulence and dispersionof a treating agent into a fluid stream. The assembly preferablyincludes lance which is disposed through a port, shroud or opening ofthe ductwork into the fluid stream so as to disperse a sorbent materialtherethrough. The assembly further includes a blade or barrier which maybe expanded or rotated to buffer or disturb a portion of the fluid flow.Specifically, the rotation of the blade or barrier creates a largerdiameter for assembly than the diameter of the port through which thelance was inserted. Thus, a system and method for improving theefficiency of the dispersion into a dry sorbent injection system isdisclosed.

BACKGROUND OF THE INVENTION

With the increase in environmental oversight, operators of power plantsare pushing to discover new and better ways to remediate potentialpollutants which are the byproducts of the power generation process. Avariety of approaches have been developed for removal or mitigation ofsuch byproducts resulting from coal fired power plants. One knownapproach is the use of dry sorbent injection (DSI) systems to reduceacid gas levels, such as such as sulfur dioxide (SO2), sulfur trioxide(SO3), sulfuric acid (H2SO4), and hydrochloric acid (HCl). DSI involvesthe addition of an alkaline material (such as sodium bicarbonate,hydrated lime, or trona) into various locations of the power plantsystem such that the acid gases react with the alkaline sorbents to formsolid salts which are removed via a particulate control device.

While DSI is a cost effective control solution, it is not without itsown processing challenges. For example it is common as one step of theprocess to disperse solid particles of alkaline materials or othertreating agent such into the gas or fluid stream in order to react withthe undesired component. Those of skill in the art know dispersionlances may be used to disperse the solid particles of treating agentinto the gaseous stream Simple ejection of the particles from suchnozzles, however, is not very effective in generating thorough mixing ofthe particles with the gas stream. Furthermore, the process can createbuildup of particulate on the lance tips such that the dispersion ofsolids may be impacted.

It is also known to use a variety of lance assemblies permit dispersionof the particulate into the fluid stream. Existing configurations,however, have achieved only limited success in improving the dispersionof the ejected particle streams. Accordingly, a need has existed for aninjection lance assembly which is fully able to produce the highlyturbulent conditions required for full and effective dispersion andmixing into the gas stream of the injected particles of the treatingagent.

A further limitation of the existing lance injection systems is thetransient nature of the use of such injection lances. Namely, there isnot necessarily a constant need for injection lances to disperseparticulate into a fluid stream. Conversely, there may be a need formultiple lance systems and/or multiple injection points in the fluidstream path to maximize the efficiency of the treatment process. Forinstance, changes in the flow rate or other characteristics of the fluidstream may require the removal or movement of such lances. Furthermore,such changes may likewise require movement or addition of baffles orother structures to create a turbulent flow wherever such lances may beplaced. However, simply adding permanently deployed baffles at multiplepoints in the system may result in a cumulative, deleterious impact onthe pressure drop for the fluid stream being processed.

In addition, the ability to add removable structures for creating aturbulent flow at the point(s) of particulate dispersion is limited as apractical matter. Specifically, the access points that are available forinserting an injection lance are typically of a limited diameterrelative to the ductwork carrying the fluid stream. However, if thebaffles or similar structures are sized such that the diameter is sizedto fit through the access points involved, the resulting use may provideinsufficient turbulence. If the particulate cannot be better dispersedin the fluid stream to be treated, the system may require higher levelsof particulate for treatment or, even worse, the system may be limitedin its ability to treat the undesirable emissions within the fluidstream.

Thus, the present state of the art reflects a need for an insertablelance injection system for use in ductwork with limited access points,wherein the system enables a broad turbulent regent for improveddispersion of a solid particulate into a fluid stream for use with drysorbent injection processes and the like.

DESCRIPTION OF THE PRIOR ART

One example of a prior art approach is found in U.S. Pat. No. 8,083,156B2 (Miller et al.). That invention teaches a lance system for dispersinga treating agent into a fluid treatment system that includes a flow ductin which a fluid stream flowing through the duct is mixed with thetreating agent. The apparatus is based on a multi-pipe lance positionedin the stream flow, where each pipe supplies a number of feed dischargenozzles, and the individual pipes branch off from the same location.Miller specifically teaches the use of multiple parallel pipes, witheach of the parallel pipes having one or more openings along theirlengths for discharging a treating agent into a fluid stream. Such anarrangement, by definition, will require a larger collective diameter ofpipes, and thus will occupy a greater volume within the fluid stream.Furthermore, nothing in Miller suggests a removable lance assembly, nordoes it teach or suggest a process to enable removable baffles orsimilar structures using access points of limited diameter. In short,Miller fails to suggest or teach how to provide a removable lanceinjection system with a structure for create a zone of turbulence in thefluid stream that is larger than the access point(s) through which thelance system is inserted.

Another approach known in the art is shown (by way of example), inliterature provided by the Industrial Accessories Company (see, e.g.,http://www.iac-intl.com/literature/PP024_SO3_Mitigation_Strategies_(—)9-14-10.pdf).This approach teaches the use of multiple lances, each having adifferent length. The design further teaches the use of a “bayonet tip”as purporting to help with even dispersion. This approach, however,creates difficulty insofar as it requires multiple lance designs to beswitched in and out of a given access port. Furthermore, this designfails to teach any ability to create a zone of turbulence in theductwork which exceeds the diameter of the given lance being employed.

What is needed is simple, cost effective and injection lance system forenabling an insertable and/or removable injection lance system,including a structure for generating a turbulence zone in the fluidstream which is greater in diameter than the access point through whichthe injection lance is placed.

DEFINITION OF TERMS

The following terms are used in the claims of the patent as filed andare intended to have their broadest plain and ordinary meaningconsistent with the requirements of the law.

A “wing” means a baffle, projection, or similar structure which may bemoved from a first retracted position to a second deployed position tocreate a zone of turbulence for the treating agent being mixed with thefluid stream. In its first retracted position, the wing is eithersubstantially in line with or surrounds the injection lance that itoperates with such that the wing does not extend substantially beyondthe shroud or lance to which it is attached.

A “blade” means the blade, propeller or similar structure which createsa zone of turbulence for the treating agent being mixed within the fluidstream. The blade has a first, secured position to enable displacementthrough an access point, but in operation the blade moves to create arotational diameter greater than the access point through which it isdisplaced.

An “actuator” or “means for actuating” refers to a spring bias, a punchrod, a cable or similar structure for enabling the movement of a bladeor wing from its first secured position to the second operationalposition.

Where alternative meanings are possible, the broadest meaning isintended. All words used in the claims set forth below are intended tobe used in the normal, customary usage of grammar and the Englishlanguage.

OBJECTS AND SUMMARY OF THE INVENTION

The apparatus and method of the present invention generally includes alance assembly for distributing particulate into a fluid stream fortreating contaminants, such as employed in a dry sorbent injectionprocess or the like. The lance assembly includes a lance or similartubular structure for inserting particulate (e.g., trona) therethroughinto the fluid stream. The lance assembly further includes a barrier,such as a wing or a blade, which typically may be attached to a shroudextending through the port which the lance is inserted, or(alternatively) in an adjacent port. The wing or blade includes a first,retracted position that permits it to minimize or eliminate the profileof the barrier in the fluid stream, and a second, deployed positionwhich expands the surface area of the wing or blade such that thebreadth of the surface area of the blade or wing is greater than thediameter of the access port through which the lance is inserted. Thelance assembly further includes a structure for urging the wing from thefirst position to the second position, as well as a structure forreversing the positioning of that barrier for removing the lanceassembly.

The immediate application of a present invention will be seen inprocessing sorbent and similar particulate for pollution control fromoperating plants in dry sorbent injection processes, though those ofskill will see that the present invention could be applied to otherfields requiring a simple and robust solution for providing a solidparticulate into a fluid stream for treatment.

Thus can be seen that one object of the present invention is to providea cost effective system for dispersing solid particulate into a fluidstream.

A further object of the present invention is to provide a lanceinjection assembly which inhibits the buildup of solid particulate onthe tip of the lance being used.

Still another object of the present invention is to provide aninsertable lance assembly through an access port for actuating abarrier, such as a blade or wing, which can be displaced, with thebarrier as deployed having a diameter substantially greater than thediameter of the access port.

Yet another object of the present invention is to provide a lanceassembly which includes a barrier such as a wing or blade, which may beretracted or removed at multiple points in the ductwork.

Still another object of the present invention is to provide a lanceassembly which does not permanently deploy baffles or similar structuresto create a zone of turbulence for dispersing particulate therethrough.

It should be noted that not every embodiment of the claimed inventionwill accomplish each of the objects of the invention set forth above. Inaddition, further objects of the invention will become apparent basedthe summary of the invention, the detailed description of preferredembodiments, and as illustrated in the accompanying drawings. Suchobjects, features, and advantages of the present invention will becomemore apparent in light of the following detailed description of a bestmode embodiment thereof, and as illustrated in the accompanyingdrawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1 a and 1 b shows sides views of the closed and open positions,respectively, of a first preferred embodiment of the invention using apair of wings and a tip configuration.

FIGS. 2 a and 2 b shows side views of the closed and open positions,respectively, of a second preferred embodiment of the invention using apair of wings and a push rod configuration.

FIG. 3 shows a perspective view of a third preferred embodiment of theinvention using a rotating wings configuration.

FIG. 4 shows a perspective view of a fourth preferred embodiment of theinvention using a downstream propeller blade configuration.

FIG. 5 shows a perspective view of a fifth preferred embodiment of theinvention using an upstream propeller blade configuration.

DETAILED DESCRIPTION OF THE INVENTION

Set forth below is a description of what is currently believed to be thepreferred embodiment or best examples of the invention claimed. Futureand present alternatives and modifications to this preferred embodimentare contemplated. Any alternatives or modifications which makeinsubstantial changes in function, in purpose, in structure or in resultare intended to be covered by the claims in this patent.

FIGS. 1 a and 1 b show a first preferred embodiment of a lance injectionassembly 10 constructed in accordance with the present invention inclosed and open positions, respectively. The lance injection assembly 10includes a tube 11 or hollow shaft for receiving solid particulatetherethrough, and further preferably includes a seating member 14 orcollar for resting upon a shroud 16 when inserted into the ductwork 18.The shroud 16 of this embodiment has attached thereto a pair of wings22, 24 by a hinged arrangement. The wings 22, 24 when retracted fold atleast partially within the shroud 16 via slits or openings (not shown)and/or (alternatively) the wings 22, 24 will fold over one another andhang below the opening of the shroud 16 within the ductwork 18. Thus, inthis first retracted or closed position, the wings 22, 24 reduce theirsurface area as exposed to the fluid stream flowing through the ductwork18, and thus improving the pressure drop of such barriers versuspermanent baffles known in the art. The second open or deployed positionof this lance injection assembly 10 is enabled as the tube 11 is pushedthrough the shroud 16. As the insertion occurs, the tip 19 of tube 11pushes the wings 22, 24 to unfold outward, thus creating a much broadersurface area across the flow direction of the fluid stream than theshroud 16 or port through which the tube 11 is inserted. In thisembodiment, if the tube is removed, e.g., if particulate does not needto be inserted at that particular access point, then the removal of thetube 11 and its tip 19 in combination with the force of gravity willcause the wings 22, 24 to fold back inwards to their retracted position.

As those of skill will understand given the teachings of thisembodiment, this embodiment of the invention can be practiced eitherthrough the case where the shroud 16 and wings 22, 24 are removablethrough the ductwork (when the wings are retracted or closed), oralternatively the shroud 16 may be permanently fixed to the ductwork 18,with only the tube 11 being inserted or removed as operationalcircumstances dictate.

FIGS. 2 a and 2 b show a second preferred embodiment of a lanceinjection assembly 20 constructed in accordance with the presentinvention in closed and open positions, respectively. This secondpreferred embodiment is in relevant part similar to the first preferredembodiment in its use of wings 22, 24. However, in this second preferredembodiment, the wings may be attached directly to the tube 21 such thatthe entire assembly 20 may be inserted through the port of the ductwork18. Since the wings 22, 24 of this embodiment are attached directly tothe tube 21 instead of a shroud or some other, separate structure, thisembodiment requires a push rod 29 to urge the wings into a deployedposition. Thus, this embodiment teaches the ability to insert and removethe entire lance injection assembly 20 through a port in the ductwork 18such that the wings 22, 24, when opened or deployed have a largerdiameter than the port of the ductwork through which it was inserted.

FIG. 3 shows a third preferred embodiment for deploying wings inaccordance with the teachings of the present invention. In thisembodiment, the lance assembly 30 includes wings 42, 44 which rotateradially outward to fold away from the shroud 36 to which it is attachedin a hinged relationship. In this preferred embodiment, the entirety ofthis assembly (i.e., both the tube 31 and shroud 36 including wings 42,44) may be inserted and removed through the port of the ductwork 18. Bycontrast with the first and second embodiments, however, the process ofretracting the wings does not rely upon gravity, and thus thisembodiment relies upon a control cable 47 or similar actuator to be usedby an operator to open and close the wings 42, 44 as needed.

FIGS. 4 and 5 show a fourth preferred embodiment of a lance injectionassembly 50 for deploying a propeller 52 on a support shaft 53, with thepropeller comprising blades 54, 55. Each blade 54, 55 includes a flatportion 56 which is substantially perpendicular to the fluid flow, anddisrupts the fluid flow and creates a zone of turbulence. Likewise, eachblade 54, 55 of this embodiment includes an angled portion 57 whichenables the rotation of the propeller 52 based upon the force of thefluid flow. In this embodiment the tube 51 may be deployed downstream(as in FIG. 4) or upstream of the propeller. In either configuration,this embodiment preferably may be inserted through two ports in theductwork 58, 59 which are separate from one another but sufficientlyproximate such that the propeller 52 creates a zone of turbulence nearthe tube 51 such that a greater dispersion of particulate passing intothe fluid stream may result. The propeller 52 preferably has a greaterdiameter than the port in the ductwork 59 through which it is inserted.The propeller, however, may nonetheless be removed through its port 59by aligning the propeller 52 and the support shaft 53 by a hook orsimilar mechanism (not shown).

The above description is not intended to limit the meaning of the wordsused in the following claims that define the invention. Rather, it iscontemplated that future modifications in structure, function or resultwill exist that are not substantial changes and that all suchinsubstantial changes in what is claimed are intended to be covered bythe claims. For instance, the numbers of wings 22, 24 used in thepreferred embodiments of present invention is for illustrative purposeswith reference to the example drawings only. Similarly, while the wingsof certain preferred embodiments of the present invention are focusedupon their attachment to shroud 16, those of skill will understand theapplicability of the present invention to configurations whereby suchattached directed to the tube for deployment upon insertion, eitherthrough a spring bias mechanism or other suitable mechanical adjustment.Likewise, it will be appreciated by those skilled in the art thatvarious changes, additions, omissions, and modifications can be made tothe illustrated embodiments without departing from the spirit of thepresent invention. All such modifications and changes are intended to becovered by the following claims.

We claim:
 1. An injection lance assembly which can be inserted into aport in ductwork, the lance assembly comprising; a) A tube for providingparticulate flow into a fluid stream within the ductwork; b) At leastone wing which is deployable within the ductwork and may be insertedthrough the port with the tube; and c) Means for actuating the wing intoa deployed position; whereby the lance assembly when deployed in theductwork has a larger diameter than the port.
 2. The assembly of claim 1wherein the means for displacing comprises a cable actuator.
 3. Theassembly of claim 1 wherein the tube further comprises a tip region, thetip region providing the means for displacing the wing.
 4. The assemblyof claim 1, wherein the means for displacing comprises a punch rod. 5.The assembly of claim 1, wherein the at least one wing comprises a pairof wings.
 6. The assembly of claim 5, wherein the wings pivot radiallyrelative to the tube.
 7. The assembly of claim 5, wherein the wingsdeploy rotationally relative to the tube.
 8. The assembly of claim 1,wherein the wings are attached to the tube.
 9. The assembly of claim 1,further comprising a shroud defining a channel with the tubedisplaceable therethrough, the wing being attached to the shroud. 10.The assembly of claim 1, wherein the tube comprises a plurality oftubes.
 11. The assembly of claim 1, wherein the tube includes aplurality of apertures along the length of the tube.
 12. The assembly ofclaim 11, wherein each of the plurality of apertures is at an axiallocation corresponding to the wing.
 13. The assembly of claim 1, furthercomprising a means for retracting the wing through the port.
 14. Theassembly of claim 13, wherein the means for retracting uses the samestructure as the means for displacing.
 15. An injection lance assemblywhich can be inserted into first and second ports, the assemblycomprising; a) A tube for providing particulate flow into a fluid streamwithin the ductwork, the tube being through the first port; b) A bladebeing displaced through the second port, the blade having first andsecond portions, the first portion providing a barrier to blunt passageof airflow therethrough, and the second portion including a curvature toencourage the rotation of the blade; whereby the blade when deployed hasa rotation diameter greater than the diameter of the second port.